Rui Maita, once an English teacher, shifted careers when talent scout Michio Hazama spotted him at a college cultural festival, captivated by Hokuto Ijuuin’s performance. Driven by a craving for adventure beyond academia, Rui channeled his fluency in English toward becoming a globally recognized idol. His lively, eccentric charm shines through a habit of peppering conversations with English expressions, aligning with his role as the "E" in S.E.M—a unit where his linguistic flamboyance offsets Michio’s stoicism and Jiro Yamashita’s quiet intensity.

Playful and relentlessly optimistic, Rui injects humor into group dynamics, once surprising his unit with strawberry-themed headbands during a live event despite mixed reactions. Michio often jests about Rui’s otherworldly quirks, yet Rui’s unwavering cheerfulness proves vital in uniting S.E.M during their rocky beginnings, fostering camaraderie amid setbacks.

An adrenaline enthusiast, Rui thrives on skiing, snowboarding, surfing, and mastering kendama tricks. His past overlaps with Hokuto in their tennis club days, and he resides in the same neighborhood as Jiro. Adopting the stage name "Michael," he humorously leans into his idol persona, even using English as a social tool at mixers pre-debut.

Though initially challenged by idol demands—remedying shaky kanji skills under Michio’s tutelage—Rui adapts diligently. His presence extends beyond S.E.M, including a brief animated cameo where he playfully bickers with peers during training, cementing his place in 315 Production’s eclectic roster. Fans affectionately dub him "Maitaru," often linking him artistically to fellow eccentric blondes, underscoring his vibrant, unconventional image.